[POWERPC] Don't use SLAB/SLUB for PTE pages

The SLUB allocator relies on struct page fields first_page and slab,
overwritten by ptl when SPLIT_PTLOCK: so the SLUB allocator cannot then
be used for the lowest level of pagetable pages.  This was obstructing
SLUB on PowerPC, which uses kmem_caches for its pagetables.  So convert
its pte level to use normal gfp pages (whereas pmd, pud and 64k-page pgd
want partpages, so continue to use kmem_caches for pmd, pud and pgd).

Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This commit is contained in:
Hugh Dickins 2007-05-09 14:38:48 +10:00 committed by Paul Mackerras
parent f1fa74f4af
commit 517e22638c
3 changed files with 19 additions and 42 deletions

View File

@ -120,19 +120,6 @@ config GENERIC_BUG
config SYS_SUPPORTS_APM_EMULATION
bool
#
# Powerpc uses the slab allocator to manage its ptes and the
# page structs of ptes are used for splitting the page table
# lock for configurations supporting more than SPLIT_PTLOCK_CPUS.
#
# In that special configuration the page structs of slabs are modified.
# This setting disables the selection of SLUB as a slab allocator.
#
config ARCH_USES_SLAB_PAGE_STRUCT
bool
default y
depends on SPLIT_PTLOCK_CPUS <= NR_CPUS
config DEFAULT_UIMAGE
bool
help

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@ -146,21 +146,16 @@ static void zero_ctor(void *addr, struct kmem_cache *cache, unsigned long flags)
memset(addr, 0, kmem_cache_size(cache));
}
#ifdef CONFIG_PPC_64K_PAGES
static const unsigned int pgtable_cache_size[3] = {
PTE_TABLE_SIZE, PMD_TABLE_SIZE, PGD_TABLE_SIZE
};
static const char *pgtable_cache_name[ARRAY_SIZE(pgtable_cache_size)] = {
"pte_pmd_cache", "pmd_cache", "pgd_cache",
};
#else
static const unsigned int pgtable_cache_size[2] = {
PTE_TABLE_SIZE, PMD_TABLE_SIZE
PGD_TABLE_SIZE, PMD_TABLE_SIZE
};
static const char *pgtable_cache_name[ARRAY_SIZE(pgtable_cache_size)] = {
"pgd_pte_cache", "pud_pmd_cache",
};
#ifdef CONFIG_PPC_64K_PAGES
"pgd_cache", "pmd_cache",
#else
"pgd_cache", "pud_pmd_cache",
#endif /* CONFIG_PPC_64K_PAGES */
};
#ifdef CONFIG_HUGETLB_PAGE
/* Hugepages need one extra cache, initialized in hugetlbpage.c. We

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@ -14,18 +14,11 @@
extern struct kmem_cache *pgtable_cache[];
#ifdef CONFIG_PPC_64K_PAGES
#define PTE_CACHE_NUM 0
#define PMD_CACHE_NUM 1
#define PGD_CACHE_NUM 2
#define HUGEPTE_CACHE_NUM 3
#else
#define PTE_CACHE_NUM 0
#define PMD_CACHE_NUM 1
#define PUD_CACHE_NUM 1
#define PGD_CACHE_NUM 0
#define HUGEPTE_CACHE_NUM 2
#endif
#define PGD_CACHE_NUM 0
#define PUD_CACHE_NUM 1
#define PMD_CACHE_NUM 1
#define HUGEPTE_CACHE_NUM 2
#define PTE_NONCACHE_NUM 3 /* from GFP rather than kmem_cache */
static inline pgd_t *pgd_alloc(struct mm_struct *mm)
{
@ -91,8 +84,7 @@ static inline void pmd_free(pmd_t *pmd)
static inline pte_t *pte_alloc_one_kernel(struct mm_struct *mm,
unsigned long address)
{
return kmem_cache_alloc(pgtable_cache[PTE_CACHE_NUM],
GFP_KERNEL|__GFP_REPEAT);
return (pte_t *)__get_free_page(GFP_KERNEL | __GFP_REPEAT | __GFP_ZERO);
}
static inline struct page *pte_alloc_one(struct mm_struct *mm,
@ -103,12 +95,12 @@ static inline struct page *pte_alloc_one(struct mm_struct *mm,
static inline void pte_free_kernel(pte_t *pte)
{
kmem_cache_free(pgtable_cache[PTE_CACHE_NUM], pte);
free_page((unsigned long)pte);
}
static inline void pte_free(struct page *ptepage)
{
pte_free_kernel(page_address(ptepage));
__free_page(ptepage);
}
#define PGF_CACHENUM_MASK 0x3
@ -130,14 +122,17 @@ static inline void pgtable_free(pgtable_free_t pgf)
void *p = (void *)(pgf.val & ~PGF_CACHENUM_MASK);
int cachenum = pgf.val & PGF_CACHENUM_MASK;
kmem_cache_free(pgtable_cache[cachenum], p);
if (cachenum == PTE_NONCACHE_NUM)
free_page((unsigned long)p);
else
kmem_cache_free(pgtable_cache[cachenum], p);
}
extern void pgtable_free_tlb(struct mmu_gather *tlb, pgtable_free_t pgf);
#define __pte_free_tlb(tlb, ptepage) \
pgtable_free_tlb(tlb, pgtable_free_cache(page_address(ptepage), \
PTE_CACHE_NUM, PTE_TABLE_SIZE-1))
PTE_NONCACHE_NUM, PTE_TABLE_SIZE-1))
#define __pmd_free_tlb(tlb, pmd) \
pgtable_free_tlb(tlb, pgtable_free_cache(pmd, \
PMD_CACHE_NUM, PMD_TABLE_SIZE-1))